1. Field of Invention
The present invention relates generally to the preservation, sanitization, fumigation and ripening of food and floral products and other items, such as mail, that are subject to various exposures and environments and potentially hazardous conditions while being stored, treated, shipped and distributed.
2. Description of Related Art
Consumers desire the freshest fruits, vegetables, meats, seafood and floral products to be available for purchase and expect them to be available year round. Food and floral growers, packers, processors and distributors have tried to satisfy this desire by shipping fruits, vegetables, meats, seafood and floral products from around the world. However, all fruits, vegetables, meats, seafood and floral products require time for logistics and distribution and require considerable time when being shipped across countries, continents and oceans and a combination thereof; for example, products shipped from the America to Europe can require more than 28 days to reach a final destination, end user or consumer. This travel time uses up valuable shelf life for the items being transported, such as but not limited to, fruits, vegetables, meats, seafood and floral products. To assure and maintain the integrity, grade, quality and sell-ability, most fruit and vegetable growers, packers and distributors must harvest these products immature or prior to be being fully ripe, to allow for the time requirements for shipping and logistics. Or, they must transport these items using a faster and more costly means.
The delay of aging or senescence, the natural form of deterioration, of fresh fruits, vegetables and floral products is the main goal in the preservation of these fresh fruits, vegetables and floral products, as senescence accounts for the majority of post-harvest losses. Senescence is endogenously controlled and is the stage when extensive catabolic reactions occur, resulting in dissolution of plant membranes. It is marked by chlorophyll loss, decreases in RNA and protein content, and tissue softening. Plants, for example, senesce to re-route materials into seeds representing the next generation; it is therefore a pre-destined apoptosis process that can only be delayed, not completely inhibited. The aging of fresh fruit and produce is increased with an increase in respiration. The rate of respiration of a fruit, vegetable or floral is inversely proportional to the shelf life of the product. A higher rate of respiration decreases the shelf life. A byproduct in the respiration of fresh fruits, vegetables and floral is an increase in ethylene production, a process referred to as climacteric. It is therefore reasonable to assume that maintaining and reducing ethylene perception and production may effectively delay senescence.
In an attempt to provide fruits, vegetables and floral products with the longest shelf life, growers have resorted to harvesting their fruits, vegetables and floral long before ripening. Early stage harvesting of fruits and vegetables, at low stages of maturity, prevents the development of natural sugars, nutrients and textures. Conventional devices, such as refrigeration and Modified Atmosphere Packaging (MAP), have been made to extend the shelf life of fruits, vegetables, floral and other perishable products. Examples of such conventional device related to Modified Atmosphere Packaging (MAP) are disclosed in U.S. Pat. Nos. 6,880,748 and 7,597,240, both of which are incorporated herein by reference in their respective entireties. The aim of conventional MAP devices is the extension of product shelf life, since fruits and vegetables are still alive and respiring when harvested and packed. Other factors, such as wounding, also affect the post-harvest shelf life extension of fresh fruits, vegetables and floral products and the success of modified atmosphere packaging.
Wounding of fresh fruit and produce also increases the respiration, thus decreasing the life span. Respiration can be measured by the oxygen uptake or by production of carbon dioxide (CO2). Respiration also produces heat and water vapor, both of which can reduce the shelf life of fresh produce and fruits. Since an aim of conventional MAP packaging systems is to increase the life span of fresh fruits, vegetables and floral, it is therefore an aim to reduce the respiration of the same, which can be achieved by decreasing the levels of oxygen (O2) within the MAP container. However, low O2 levels, one to two percent by volume, create ideal conditions for pathogens (or germs), such as clostidium botulinum. The increase of heat, production of water and low O2 are problems often found with conventional MAP devices.
As mentioned above, ethylene, a plant hormone, plays a large role in shelf life of fresh fruits and produce and causes a marked increase in respiration rates and enhances ripening and senescence. In some commodities, accelerated aging and the initiation of ripening can occur following exposure to ethylene concentrations as low as 0.1 ml/l. As senescence begins, spoilage due to indigenous bacteria can be augmented. Ethylene is also a byproduct of the aerobic combustion of hydrocarbons, and it is therefore important during the handling of produce to maintain low levels of environmental ethylene, which are often increased by forklifts and other machinery. Different biological structures of assorted produce varieties contribute to the product's sensitivity response to ethylene, as well as the response to O2 and CO2. Furthermore, different stages of maturity, cultivar and post-harvest storage conditions also influence sensitivity to ethylene. Conventional packaging and some MAP systems fail to include control measures to minimize production of ethylene following harvest. The present invention includes such measures as storage in a modified atmosphere at optimal and or reduced temperatures (below traditional recommended injury threshold) and oxidizing the ethylene by various chemical and physical means. Ethylene Absorbing Packets (EAP) may be employed to extend the shelf life of fruits, vegetables and flowers in a packaged or bulk environment. Ethylene absorbing packets are constructed with natural occurring zeolites. EAPs remove unwanted ethylene gas through the oxidation process, thereby ensuring the quality of freshness of the product, while in transit or in storage.
While conventional MAP devices do provide some means to control the atmosphere of packaging, conventional MAP devices fail to control the suppression or release of gases known to enhance or suppress the ripening of fresh fruits and produce, such as CO2, O2 Ethylene and Nitrogen.
Further, conventional MAP devices fail to provide a delivery system to regulate or activate ingredients in order to reduce oxygen levels. Oxygen supports the growth of micro-organisms, causes product color changes, and causes rancid odors in packaged foods.
The conventional MAP packaging systems also fail to provide for the sanitization of the products during shipping and ripening of the products. Another hazard in the shipment of fresh fruits and produce is the control of micro-organisms and the presence of live insects. Conventional MAP devices fail to provide a method to enable an insecticide to be dispensed within the MAP to control micro-organisms and insects. Such a failure limits the shipment of some fresh fruits and vegetables to many countries.